As IC wafer fabrication process technology advances from sub-micro to nanometer, the heat generated by IC increases greatly due to the increased number of transistor as well an increase in the device current leakage. Therefore, the package and system thermal performance becomes a concern for high performance products.
A typical prior art flip-chip BGA package 100 for a high performance IC 106 is shown in FIG. 1. The package has a heat sink 107 made of a material with a high coefficient of thermal conductivity and fan 109 to handle the IC power dissipation. The heat generated by the integrated circuit 106 is transferred to the heat sink 107 by conduction. The fan 109 creates an airflow to dissipate the heat from the heat sink 107 by convection. The fins 108 on the heat sink 107 maximize surface area contact with the air which advantageously increases conduction between the heat sink 107 and the air. The flow of the air is represented by arrows 120. However, as seen from the air flow 120 only the top side of the package is effectively for heat dissipation, due to the lack of air flow at the other areas of the IC 106 such as the side and bottom, substrate surface 103 and printed circuit board surface 101. Thus, the effects of the prior art heat sink are not maximized.
It is therefore an object of the present subject matter to obviate the deficiencies of the prior art and present a heat sink for an integrated circuit including a heat conductive material having a generally planar shape adapted to receive an IC chip on a bottom surface and adapted to be in thermal connection with the IC chip. The heat sink includes fins extending from and above a top surface of the heat sink; and a plurality of slots providing fluid communication between the top surface and the bottom surface of the heat sink.
It is also an object of the present subject matter to present an integrated circuit package including a substrate; a integrated circuit positioned on the substrate, and a heat sink in thermal connection with the IC chip. The heat sink includes a plurality of fins and a plurality of fluid passages between a top surface and a bottom surface of the heat sink. The integrated circuit package also includes a fan adapted to force fluid from the top surface to the bottom surface.
It is further an object to present a method to increase heat dissipation in a IC package, the package including a substrate; an integrated circuit positioned on the substrate, a heat sink in thermal connection with the IC chip and a heat sink comprising a plurality of fins. The method includes the step of forming a plurality of fluid passages between the top surface and a bottom surface of the heat sink.
These and many other objects and advantages of the present subject matter will be readily apparent to one skilled in the art to which the subject matter pertains from a perusal of the claims, the appended drawings and the following detailed description of the preferred embodiments.